If you haven't read this New York Times story about the history of insulin, please do. I'll wait.
The sentence that hit me where I live was this one:
"Diabetes was the first illness which forced them [doctors] to cede some medical authority to the patient, said Jean Ashton, one of the exhibit’s curators. With insulin, diabetics suddenly acquired both the right and the responsibility to maintain their own health."
I guess I don't really need to expand on that, do I?